Internal-combustion engine



A. H. R. FEDDEN.

INTERNAL COMBUSTION ENGINE.

APPLICATION mu) Nov. 21. 1918 Patnted July 13, 1920.

3 SHEETSSHEEI 1.

A. H. R. FEDDEN.

INTERNAL COMBUSTtON ENGINE.

APPLICATION FILED NOV-21,1918.

1. 246,534. Patented July 13, 1920.

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INTERNAL COMBUSTION ENGINE.

APPLICATION FILED NOV. 21. 1918.

1,346,534. Patented July 13, 1920.

3 SNEE'lS-SHEEI 3- W imsses .Dwenor a Z (L REALM %wm QMQ ALFRED HUBERT ROY FEDDEN, F BRISTOL, ENGLAND.

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Specification of Letters Patent. I

Patented July 13,1920.

Application filed November at, 1918. Serial No. 263,590.

To all whom it may concern:

Be it known that I, ALFRED HUBERT ROY FEDDEN, a subject of the King of England, residing at F ishponds, Bristol, England, have invented certain new and useful Improvements in Internal Combustion Engines, of which the following is a specification.

This invention is for improvements in or relating to the cylinders of air-cooled internal-combustion engines and particularly cylinders of the known type having a barrel with an integral head at or near one end, and a cap secured in close contact with the head forthe purpose of conveying the heat therefrom and dissipating it. Such cylinders are usually formed with the valve-guides in the cap, and the valve-seats may be either on the cap, as is shown, for example in the specification of Henriods British Iietters Patent No. 13466 of 1908, or on the integral head as is shown in the specification of Daimlers British Letters Patent No. 103,960 dated 9th September 1916. In these constructions, however, the cap is located 0n the head by one or more projections on one of the 0pposed faces spigoting into the other face, or by upstanding flanges on the integral head engaging the cap. Since the conduction of heat from the integral head to the cap is largely dependent on the area and intimacy of surface contact between head and cap it is important that the two surfaces should be properly bedded together in the first instance, and further, maintained incontact under all conditions of temperature and stress to which they are subjected.

According to one feature of the present invention the two abutting surfaces are both machined fiat without any projection or 'protuberances and these flat surfaces are not only placed in close contact with one another initially but the cap is stiffened against buckling and also is further maintained, as

i to its under face, in contact with the upper face of the head not only by means which hold the centers of the two faces together but also by studs disposed around the centers within the radius of the cap. The location of the cap on the head is effected by one or more separate dowel-members which engage recesses in each of the faces. Preferably these dowel-members are made of material of highther'mal conductivity, such as copper, and they may be arranged at such points on the integral head as require special cool- 1ng, for earample around the exhaust ports.

According to another feature of the invention the plate or flange of the cap which butts against the integral head is radially extended around its periphery to form a cooling fin, the object being to provide a short path of conduction from the head to the fin and dissipate part of the heat as soon as possible.

Other features of the invention will now be described with reference to the particular construction illustrated and the novel details pointed out in the claims appended to this specification.

In the accompanying drawings-- Figure 1 is a longitudinal section through a complete cylinder and cap on the line 1, 1 of Fig. 3;

Fig. 2 is an elevation of the cap which fits on the barrel;

Fig. 3 is a plan of Fig. 1;

Fig. at is a plan of the barrel and integral head, with the cap removed.

Like reference characters indicate like parts throughout the drawings.

Referringto these drawings, the cylinder A, which is preferably made of steel, is provided from the top downward with cooling-. fins A situated over the greater part of the length of the cylinder. The combustion chamber A is preferably of larger diameter than the barrel in order to provide sufiicient area in the head for the valves, and to afford a ring or corrugation constituted by the parts R R R in Fig. 1 to strengthen and stiffen the top end of the cylinder. The head A of the barrel is integral with it, and is quite flat on top and devoid of upstanding pro ect1ons; it has the valve-ports suitably spaced init. In the form shown there are two exhaust-ports A and one inletort A Valve-seats A A respectively for t e usual tappet 0r mushroom'valve are formed on the inner face of the inte ral head A and recesses A A are provider? on the outer face of the integral head around each of these ports, a recess A being provided at each exhaust port and a recess A at the inlet-port. If desired the recess A around the inlet-port ma be omitted.

hese recesses are filled b rings B B which stand above the outer fiice of the integral head A and constitute the dowelmembers above-mentioned. Otherwise this flat and smooth all over its under face which is held in intimate contact with the head A Ports C G in the lower face of the plate C register with the ports A A and are recessed in a similar manner to receive the rin s B B The inlet and exhaust passages which lead respectively to these ports are bounded and constituted by hoods or walls 0 C cast integral with the plate G as is a centrally disposed pillar or boss C and all these parts are further connected together by a series of cooling-fins cast integrally with them. The two exhaust hoods U are arran ed so that they diverge and the coolin -fins a between them are spaced far enoug apart (see Fig. 2) to insure that a liberal flow ofair shall be possible between them. On the outer sides of the exhaust passages, the fins C are more closely spaced as they are unobstructed and free air can flow easily to and away from them.- A special cooling-fin C is constituted by a peripheral extension of the plate (1, and this fin is arranged close to the cylinder-fins A Its special function is to provide a means of dissipating heat from the head A as close as possible to that head. It is not generally necessary to provide cooling-fins on the inlet passage wall 0 as this is sufficiently cooled by the incoming fresh charges; fins may be provided, however, if considered desirable, in special cases.

Other details of construction which may be noted are that suitable openings E E are provided in the head A and cap' G respectively for the fitting, of sparking plugs. Valve-guides E E are fitted inv suitable bosses in the walls of the inlet and exhaust passages as shown in Fig. l. A bracket E is provided above the inlet passage (see Fig. 3) for carrying the valve-operating gear. Other arrangements and numbers of valves may be used, and instead of a single central boss or illar C, there may be two or more provide according to the arrangement of valves required and space available.

As mentioned above, the function of the separate cap C is thatit shall conduct away the heat from the integral head A", and in order that this may be done efficiently it is important that they should be secured together in intimate contact, and furthermore,

eeasaa that the cap should be formed and secured in such manner that under working conditions, this intimate contact is not impaired by expansion or buckling of one of the two parts away from the other.

Accordingl the cap is stiffened against buckling by t e hoods and radiation fins integral with it as aforesaid and is secured on the head by a large number of studs such as st disposed around the center but within the radius R of the head so that the head shall not buckle between the edges and the middle and is also secured in the center by a stud 86 which conveniently extends through the central boss C (or'bosses, if there are more than one). These studs extend up through the plate G or through the cooling-fins as well as that plate, according to their positions in the cap, so as to render the nuts easily accessible for tightening up.

A factor contributing to the maintenance of the desired intimate contact is the very rigid construction of the cap with the central pillar. and cooling-fins reinforcing and supporting the hoods C C so that no yielding or working of the cap itself can take place. This strength in the cap is also of great value in supporting the integral head A against the stresses to which it is subjected by the explosions in the cylinder, and

it is possible therefore to make the integral head lighter than would otherwise be the case.

It will be observed thatthe central pillar C fulfils a double function, for in addition 1| to contributing to the strength of the cap, it also provides a path for the conduction of heat away from the center of the head A, such heat being dissipated from the fins C and the upper part of the pillar. Further, I

as pointed out above, the copper rings B B especially those around the exhaust-port, will convey heat awazy rapidly from the head A and valve-seats 6 thereby maintaining the exhaust valves cool and insuring a 1 larger life of the valves than would otherwise be the case. The rings thus also have a double function, of which one part is that they serve as dowel-members for the location of the cap on the head, and the 1 other part is that they serve as heat-conductors for conveying heat away from the I cylinder-head A.

What I claim as my invention and desire to secure by Letters Patent is 1 1. In an internal combustion engine the combination of a cylinder having the highest portion of its head formed integral wlth it as a flat plate devoid of upstanding projections a cap having hoods for inlet and exhaust passages and parallel radiation-fins connecting them formed integrally with it and having a flat bottom plate devoid of upstanding projections, and means securing the cap to the cylinder head with the said flat 1 plates in intimate contact with one another, substantially as set forth.

2. In an internal combustion engine the combination of a cylinder having the highest portion of its head formed integral with it as a flat plate devoid of upstanding projections, a cap having hoods for inlet and exhaust passages, a central pillar or pillars and parallel radiation fins connecting said hoods and pillars all formed integral with said cap, said cap further having a fiat bottom plate devoid of upstanding projections and means securing the cap to the cylinder head with the said flat plates in intimate contact with one another, substantially as set forth.

3. In an internal combustion engine the combination of a cylinder having the highest portion of its head formed integral with it as a flat plate devoid of upstanding projections, a cap stiffened against buckling and having a fiat bottom plate devoid of up standing projections, means securing the cap to the cylinder head with the said fiat plates in intimate contact with one another and dowel-members made of material of higher thermal conductivity thanthe parts in which they are inserted interposed between said flat plates to engage recesses in each of them, substantially as set forth.

4. In an internal combustion engine the combination of a cylinder having the highest portion of its head formed integral with it as a fiat plate devoid of upstanding projections, a cap stiffened against buckling and having a flat bottom plate devoid of up standing projections but having a radiation fin extending in the same plane as the plate around the periphery of the plate and means securing the cap to the cylinder head with the said flat plates in intimate contact with one another, substantiall as set forth.

5. In an internal combustion engine the combination of a steel cylinder having the highest portion of its head formed integral with it as a flat plate devoid of upstanding projections, an aluminium cap stiffened against buckling by hoods for inlet and exhaust passages and a central pillar or pillars and parallel radiation fins connecting them all formed integral with the cap, said cap further having a flat bottom plate devoid of upstanding projections but with a radiation fin extending around its periphery, each of said flat plates being formed with ports and with annular recesses around two ports on the opposed faces of the plates, copper rings adapted to enter said annular recesses, and means securing the cap to the cylinder head both at the center and around the edge with the said flat plates in intimate contact with one another substantially as set forth.

In testimony whereof I afiix my signature.

ALFRED HUBERT ROY FEDDEN. 

